There has been conventionally known a steering control technique in which a traveling path of a preceding vehicle is acquired or calculated and a curve shape of a lane on which a host vehicle is traveling (host vehicle lane) is predicted from the traveling path of the preceding vehicle (see Japanese Patent Application Publication No. 2013-226973).
However, in Japanese Patent Application Publication No. 2013-226973, it is difficult to predict the curve shape of the host vehicle lane from a traveling path of a surrounding vehicle traveling in a lane other than the host vehicle lane.